Underfeed retort, including ring constructed tuyere means



Aug. 21, 1951 P. c. MALMSTEN 2,565,318

UNDERFEED RETORT, INCLUDING RING CONSTRUCTED TUYERE MEANS 2 Sheets-Sheet 1 Filed March 6, 1947 I I I I I I I I zzzzz Q In": IN V EN TOR.

ATTORNEY Aug. 21, 1951 P. c. MALMSTEN 2,565,318

UNDERFEED RETORT, INCLUDING RING CONSTRUCTED TUYERE MEANS Filed March 6, 1947 2 Sheets-Sheet 2 /& A

IN VEN TOR.

, iakafw ATTORNEY Patented Aug. 21, 1951 UNDERFEED Ramona; incrnnmo: RING CONSTRUCTED TUYERE MEANS Philip C. Malmst'en, Milwaukee, Wis., assignor to A. O. Smith. Corporation, Milwaukee, Wis, a corporation ofiNewyYork Application March 6, 1947., SerialNo. 73.2;821

. 4 Glaims.

Thisinvention relates to a stoker retort assembly and is particularly directed to the construction of the tuyere portion of the assembly.

One object of the invention isto provide a retort assembly in which the tuyere portionhas improved service life without burning out or breaking.

Another object of the invention is-to provide the tuyere portion of the retort assembly with'maximum air opening permissible for ordinary coal, affording maximum efficiency of the blower unit.

Anotherobject is to provide a tuyere construc tion in which generallyhigh grade alloy metal is employed affording longer life and heat resistant qualities and reducing costsof replacements.

Another object is to provide the'tuyere por-- tion of the retort assembly of a plurality of'tuyere members stamped from plate metal.

A further object is toprovide the retortassembly with tuyere members of plate metal which are individually replaceable.

These and other objects and advantages of the invention will appear hereafter from. the following description of anrembodiment of the invention. illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a top plan view of the retort assem bly with parts broken away and sectioned;

Fig; 2 isv a longitudinal vertical section: taken on line 2-2 of; Fig. 1,;

3+3 ofliig. l; and

. Fig. 4. is a. fragmentary section taken on line 4-.-4 ofFig. 1.

The retort assembly of the invention comprises in general the retort elbow I- partially encircled by the Wind box 2 which is radially spaced: from: the elbow to form an air'chamber therebetween and provided Withv a flanged. rim 3' to: support the tuyere section 4.

Wind box 2' is constructed of sheet metal formed and welded into a circular wall into one side of which extend the coal duct 5 and the air duct ii. Theicoal. duct 5 connects with elbow l to supply coal to the burner from underneath by means of the feed screw 1 operated therein by suitable driving means, not shown. The air duct 6 supplies air under forced draft from a source, not shown, to wind box 2 for flow to, tuyere section 4 to aid in the combustion of the fuel being burned.

The. circular flange 8 extends horizontally outwardly a substantial distance from the upper portion of retort elbow l to the wall of wind box 2 and the outer end of the flange is welded. to the wind box to close off the top. of the same. Cir- V ,taper of. elbow I;. here i5 is, substantially the same, but the inner diameter. of, the rings decreases from, thetop ring cumferentiallyspaced openings 9 are provided in flange 8 for-flowto tuyere section 4 of the air supplied to wind box 2 by airduct 6.

The bonnet In of tuyre section 4 has a circular outer wall which is supported within annular groove H in flange 3 of wind box 2 and an'inwardly turned flange l2 extending horizontally from the upper end of the outer wall and surrounding a central opening intothe firebox ofthe unit. The joint betweenbonnetl0 and flange 3 is sealed by a suitable gasket or cement. Bonnet i0 is secured to flange 8 of retort elbow I by boltsi3 which extend diagonally downwardly through the bonnet and are threaded into flange 8. The heads of'bolts [3 when in place are inset in bonnet it within suitable recesses l4 provided on opposite sides ofthe bonnet to protect the bolt heads in service.

The firebox of tuyere section 4 which is assemvide the horizontal. tuyere. openings I! therebetween for flow of the received by the bon- -net into the burner portionrof. tuyere section 4.

The lowermost tuyeremember I5, is spot welded to. the flanged upperend of, the tuyre spout portion [8 of the fireboxwh chv is supported within annular groove IS in the upper portion of retort elbow I- Spout 183s inwardly spaced fromthe circular wall of bonnet ill to provide a substantween spout: l8 and elbow l is sealed by a. suit- The. uppermost tuyere member 15 is separated into halves to avoid the, wall of bonnet Ill at recesses IA.

The spacing; rivets: It havev longitudinally spaced flattened portions which, fit into complementary slots 20 in the outer edge of each tuyre member and to form the rivet, with ver- The head. 22 of each rivet engages the within the holes provided in recess Hl in bonnet ill to receive the rivets By spot weldin the lowermost tuyere member to tuyere spout 18, when. the rivets are in. place, the. entire retort assembly structure is secured together.

Spout I8- is of conical shape to carry out the The outer diameter of mem- 3 to the bottom ring to carry out the taper of re-- tort elbow I and spout l8 and provide the burner portion of the retort assembly of generally conical shape. The opening through flange l2 of bonnet l also cooperates to provide the firebox with a conical central opening.

The inner edge 23 of each member 15 is flared upwardly and into the horizontal opening I! between the lower tuyere member and the adjacent tuyere member above to deflect the air upwardly which flows into the burner pot. Inner edge 24 of the bonnet I0 is similarly flared except at recesses M to similarly deflect the infiowing air. The tuyere members are free of engagement with each other to prevent any substantial restriction of air flow between the tuyre members when air is flowing into the unit through air duct 6..

The retort shown has the horizontal tuyere openings I! extending about the circumference of the burner without a break except for interruption by the walls of recesses l4 so that a uniform supply of air is provided from all sides as the coal moves upwardly through the central burner space of the retort.

The shape of inner edge 23 of tuyere members l5 and edge 26 of bonnet It prevents undue coal deposit and eventual clogging of the burner by providing a clear path for expansion of the body of coal as it gradually moves upwardly past tuyere members l5. In addition the location of the deflecting edges within the tuyere openings and spaced from the next above adjacent tuyere member does unduly obstruct the tuyere openings and provides for a maximum draft through the tuyere openings I? and deflection of the same upwardly.

There are three tuyere members i5 shown in the drawings but the number may be varied de-- pending on the size of firebox desired in the burner. The outer edges of the two lowermost tuyere members 15 are provided with suitable slots for the passage .of bolts [3 for securing the bonnet to flange 8 of retort elbow l.

The bonnet it may be provided with a plurality of openings 25 spaced about the circumference thereof to supply air to any coal which may fall over the top of the bonnet.

The tuyere members it are fabricated from heat resistant alloy plate stock and are readily pressed to shape. The manner'of construction of the tuyeres or" the invention is an improvement over cast or like tuyres wher diflicult casting problems are involved to provide suitable tuyere openings. The assembly of the retort is likewise rapid and less costly and the individual tuyre members may be replaced.

Various embodiments of th invention may .be employed within the scope of the accompanying claims.

I claim:

1. In a retort assembly for stokers having a top central firebox supplied with coal from beneath and a surrounding housing having a chamber for supplying air to the firebox through tuyeres, a tuyere construction comprising a plurality of continuous plate metal ring members spaced vertically apart and disposed as the upper portion of the side walls of the firebox with the space between said plate members being substantially uniform and continuous circumferentially of the retort assembly to provide an equalized supply of air from all sides from the chamber in said housing, upwardly bared edges provided on the inner circumference of said plate members and projecting within the tuyere open ings and removed from the lower plate member and the next above adjacent plate member to deflect inflowing air and coal upward without substantial restriction of the tuyere openings, a plurality of tieing members extending through the outer end portions of the plate members to secure the plate members together, and means on said tieing member vertically spacing said plate members in fixed spaced relation.

2. In a retort assembly for stokers having a top central firebox supplied with coal from beneath and a surrounding housing having a chamber for supplying air to the firebox through tuyeres, a tuyere construction comprising a plurality of continuous plate metal ring members stacked one above the other and disposed as the upper portion of the side walls of the firebox, means securing the lowermost plate member to the lower portion of the'wall of the firebox, a plurality of tieing members extending through slots in said plates and securing the same to the wind duct and lower portion of the firebox, and shoulders provided on said tieing members to uniformly space the plate members vertically apart around the circumference of the firebox to provide an equalized supply of air to the firebox from all sides.

3. In a retort assembly for stokers having an open top central firebox supplied with coal from beneath and a surrounding housing having a chamber for supplying air to the firebox through a tuyere section, a tuyere construction comprising a plurality of substantially continuous plate metal members each having a central opening and spaced vertically apart and disposed as the upper portion of the side walls of the firebox with the vertical space between said plate members being substantially uniform and continuous circumferentially of the firebox, and combined spacing and securing means extending through the outer portions of said rings to secure and space the rings at their outer ends.

4. In a retort assembly for stokers having an open top central firebox supplied with coal from beneath and a surrounding housing having a chamber for supplying air to the firebox through a tuyre section, a tuyre construction comprising a plurality of continuous plate metal members each having a central opening and construct ed of high heat resistant alloy pressed metal stock and spaced vertically apart and disposed as the upper portion of the side walls of the firebox with the space between said plate members being substantially uniform vertically and continuous circumferentially of the firebox, and combined spacing and securing means extending through the outer portion of said rings to secure and space the rings at their outer ends.

PHILIP C. MALMSTEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,912,876 Warner June 6, 1933 2,033,919 Burton Mar. 17, 1936 2,039,042 Webb Apr. 28, 1936 2,149,182 Powers Feb. 28, 1939 2,341,622 Kaufman Feb. 15, 1944 FOREIGN PATENTS Number Country Date 753,140 France July 31, 1933 

